Slim Hole Pipe Cutting Apparatus

ABSTRACT

A pipe cutting apparatus for insertion through a slim hole into a deep well casing includes a cylindrical body member having a side wall defining open top and bottom ends and an interior area. The side wall defines a pair of slots. A pair of cutting members includes a first end coupled to the side wall adjacent one end of a respective slot and a second end extending into a respective slot. Each cutting member is inwardly biased through a slot into the interior area. The side wall includes a diameter smaller than a diameter of the well casing and larger than that of the tubing such that respective cutting members bear against the tubing when the body member is inserted into the deep well casing. A blade is coupled to each second end of respective cutting members and configured to cut the tubing when the body member is rotated.

BACKGROUND OF THE INVENTION

This invention relates generally to pipe cutters and, more particularly, to a slim hole pipe cutting apparatus for use in cutting damaged tubing situated in a deep well casing.

A major challenge with maintaining operation of a deep well, such as an oil well, is how to deal with tubing that has become damaged or has otherwise lost efficient communication of oil to the surface. More particularly, thousands of feet of modular tubing pieces extend deep into the ground and one or more of them may need to be replaced. If a segment of tubing needs to be replaced, then the damaged section needs to be severed from adjacent pieces, removed, and replaced.

Therefore, it would be desirable to have a cutting apparatus that may be inserted into a narrow hole of a deep well casing, positioned adjacent the tubing in need of repair and then rotated to cut away the offending section of tubing such that a new segment of tubing may be moved into position. Further, it would be desirable to have a cutting apparatus having a pair of inwardly biased blades that can surround a damaged tubing segment and then be rotated so as to cut through the walls of the damaged tubing from its outside diameter.

SUMMARY OF THE INVENTION

A pipe cutting apparatus according to the present invention is useful for cutting damaged tubing internal to a deep well casing and includes a body member having a continuous side wall defining opposed open top and bottom ends and an interior area therebetween. The side wall defines a pair of longitudinally extending slots. A pair of cutting members each having a first end is coupled to the side wall adjacent one end of a respective slot and a second end extends into the respective slot. Each cutting member is inwardly biased such that the second end extends inwardly through the slot into the interior area.

The side wall includes a diameter smaller than a diameter of the well casing and larger than a diameter of the tubing such that respective cutting members bear against the tubing when the body member is selectively inserted into the deep well casing. A blade is coupled to respective second ends of respective cutting members configured to cut the tubing when the body member is rotated.

Therefore, a general object of this invention is to provide a pipe cutting apparatus that may be inserted into the narrow opening of a deep well casing and positioned to surround a damaged tubing segment.

Another object of this invention is to provide a pipe cutting apparatus, as aforesaid, having a pair of blades that are inwardly biased against the tubing segment and configured to cut through the wall of the damaged tubing segment as the pipe cutting apparatus is rotated.

Still another object of this invention is to provide a pipe cutting apparatus, as aforesaid, having a cut lip at one end configured to clear away debris as the apparatus is lowered into a deep well casing.

Yet another object of this invention is to provide a pipe cutting apparatus, as aforesaid, that is easy to utilize from a deep well installation.

A further object of this invention is to provide a pipe cutting apparatus, as aforesaid, that can cut tubing from the tubing's outer diameter in a slim hole environment.

Other objects and advantages of the present invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, embodiments of this invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a slim hole pipe cutting apparatus according to a preferred embodiment of the present invention;

FIG. 2 a is a side view of the pipe cutting apparatus as in FIG. 1;

FIG. 2 b is a sectional view taken along line 2 b-2 b of FIG. 2 a;

FIG. 2 c is an isolated view on an enlarged scale taken from a portion of FIG. 2 b;

FIG. 3 is a top view of the cutting apparatus as in FIG. 1;

FIG. 4 a is a top view of the cutting apparatus illustrated in the context of being positioned inside a deep well casing having a slim hole opening; and

FIG. 4 b is a sectional view taken along line 4 b-4 b of FIG. 4 a.

DESCRIPTION OF THE PREFERRED EMBODIMENT

A slim-hole pipe cutting apparatus according to a preferred embodiment of the present invention will now be described with reference to FIGS. 1 to 4 b of the accompanying drawings. The pipe cutting apparatus 10 includes a body member 20 and at least one cutting member 36 coupled to the body member 20 that is configured to cut a tubing segment from the tubing segment's outside diameter when positioned inside the slim hole environment of a deep well casing 12.

The pipe cutting apparatus 10 includes a body member 20 having a generally cylindrical configuration defining open top 26 and bottom 28 ends and defining a hollow interior area between the ends (FIG. 1). More particularly, the body member 20 includes a continuous side wall 22 that defines at least one slot 34 positioned in longitudinal orientation between the top 26 and bottom 28 ends. Preferably, the side wall 22 defines a pair of opposed slots 34 displaced from the bottom end 28 with each having a generally rectangular configuration although other slot configurations would also work. The pair of slots 34 are aligned with one another (opposite one another) and extend only partially between opposed ends of the body member 20.

An inner surface of the side wall 22 of the body member 20 may include a threaded section 32 (FIG. 1). The threaded section 32 enables the body member 20 to be coupled to a line of complementary tubing members being lowered into a deep well casing 12. As is well known in the art, a plurality of tubing segments may be threadably coupled together to extend hundreds or even thousands of feet below a ground or sea surface and then to deliver oil, gas, or water back to the surface. One-by-one, tubing segments are added as a tubing line is inserted into a deep well casing 12.

The body member 20 may include a diameter larger than diameter of tubing in a line of tubing segments already in the well casing 12 so as to surround the existing segments as it is lowered (FIGS. 4 a and 4 b). It is understood that the diameter of the side wall 22 is smaller than a diameter of the well casing 12 itself so as to be lowered therein.

The bottom end 28 of the body member 20 may include a “cut lip” portion 30 (FIG. 1). Specifically, the cut-lip portion is a part of the side wall 22 but is not continuous and does not extend 360 degrees. The cut-lip portion is able to act in the manner of a scraper blade so as to dislodge debris encountered within the well casing 12 while being lowered therethrough. The cut-lip portion 30 may also direct debris caused by a cutting operation away from the body member 20.

The pipe cutting apparatus 10 includes at least one cutting member 36 having a first end 38 coupled to the side wall 22 adjacent an end of the at least one slot 34 and having a second end 40 extending into the slot 34. The first end 38 may be coupled to the side wall 22 with a mounting plate 42. The mounting plate 42 may be welded using nickel silver. Preferably, the pipe cutting apparatus 10 includes a pair of cutting members 36 extending into respective slots 34. Each cutting member 36 is biased inwardly such that respective second ends 40 extend through respective slots 34 and into the body member interior area so as to bear against a tubing segment. Each cutting member 36 may have a generally linear configuration constructed of spring steel.

Each cutting member 36 includes opposed side edges extending longitudinally between first 38 and second 40 ends. A blade 44 is coupled to respective second ends 40 of each cutting member 36 adjacent a first side edge 46. The blade 44 is configured to cut into the outside of a tubing segment 14 when the cutting member 36 bears against the tubing segment 14 and the body member 20 is rotated, such as by operation of a power swivel unit (not shown) at the surface of the well casing. Each blade 44 may be configured to only cut a tubing segment 14 when rotated in one direction—such as to the right—and not if rotated in an opposite direction—such as to the left.

In use, the slim-hole pipe cutting apparatus 10 may be utilized to cut a wall of a tubing segment 14 within the narrow environment of a deep well casing 12. The apparatus 10 must first be inserted into the casing 12 and lowered to just the exact position of the tubing segment 14 to be severed and later replaced. This can be determined by measurement, video camera, or the like. The body member 20 includes a diameter smaller than that of the casing 12 but larger than that of the tubing segments 14. As such, the body member 20 may be inserted through an open top end of the casing and, by threadably connecting a plurality of complementary tubing members, descended until it surrounds or encases the target tubing segment. When positioned accordingly, the second ends 40 respective inwardly biased cutting members 36 and respective blades 44 bear against the target tubing segment as described above. When properly positioned, the body member 20 and, in fact, all of the complementary tubing members may be rotated by a power swivel unit for a desired period of time and at a desired RPM. Accordingly, the blades 44 cut into an outer surface of the target tubing member and, in time, sever it completely. The severed tubing segment may be removed entirely, allowed to fall to the bottom of the casing, or otherwise disposed of using other techniques known in the art. Similarly, the targeted tubing segment may be replaced so that the well can be put back into service again.

It is understood that while certain forms of this invention have been illustrated and described, it is not limited thereto except insofar as such limitations are included in the following claims and allowable functional equivalents thereof. 

1. A pipe cutting apparatus for use in cutting tubing that extends internally within a deep well casing, said cutting apparatus comprising: a body member having a continuous side wall defining opposed open top and bottom ends and an interior area therebetween; wherein said side wall defines at least one longitudinally extending slot; at least one cutting member having a first end coupled to said side wall adjacent an end of said at least one slot and a second end extending into said at least one slot, said at least one cutting member being normally biased such that said second end extends through said slot into said interior area.
 2. The pipe cutting apparatus as in claim 1, wherein said side wall of said body member includes a diameter smaller than a diameter of the well casing and larger than a diameter of the tubing such that said at least one cutting member bears against the tubing when said body member is selectively positioned between the internal tubing and the deep well casing.
 3. The pipe cutting apparatus as in claim 2, wherein: said at least one cutting member includes opposed side edges extending longitudinally between said first and second ends; and a blade is coupled to said second end of said at least one cutting member adjacent said first side edge, said blade being configured to cut the tubing when said cutting member is bearing against the tubing and said body member is rotated.
 4. The pipe cutting apparatus as in claim 1, wherein said first end of said at least one cutting member includes a mounting plate coupled to an outer surface of said side wall of said body member.
 5. The pipe cutting apparatus as in claim 1, wherein an inner surface of said side wall adjacent said top end of said body member includes a threaded configuration.
 6. The pipe cutting apparatus as in claim 1, wherein said bottom end of said body member includes a cut lip configuration.
 7. The pipe cutting apparatus as in claim 1, wherein said at least one cutting member is constructed of spring steel configured to bend inwardly toward said interior area so as to contact the tubing when said body member is inserted into the well casing.
 8. A pipe cutting apparatus for use in cutting tubing that extends internally within a deep well casing, said cutting apparatus comprising: a body member having a continuous side wall defining opposed open top and bottom ends and an interior area therebetween; wherein said body member defines a pair of opposed longitudinally extending slots extending partially between said open top and said bottom end; and a pair of cutting members each having a first end coupled to said side wall adjacent an end of a respective slot and a second end extending over said respective slot, each said cutting member being inwardly biased such that said second end extends inwardly through said slot into said interior area.
 9. The pipe cutting apparatus as in claim 8, wherein said side wall of said body member includes a diameter smaller than a diameter of the well casing and larger than a diameter of the tubing such that respective cutting members bear against the tubing when said body member is selectively positioned between the tubing and the deep well casing.
 10. The pipe cutting apparatus as in claim 9, wherein: said respective cutting members include opposed side edges extending longitudinally between respective first and second ends; and a blade is coupled to respective second ends of said respective cutting members adjacent respective first side edges, said blade being configured to cut the tubing when said respective cutting members are bearing against the tubing and said body member is rotated.
 11. The pipe cutting apparatus as in claim 8, wherein said first end of each cutting member includes a mounting plate coupled to an outer surface of said side wall of said body member.
 12. The pipe cutting apparatus as in claim 8, wherein an inner surface of said side wall adjacent said top end of said body member includes a threaded configuration.
 13. The pipe cutting apparatus as in claim 8, wherein said bottom end of said body member includes a cut lip configuration so as to clear debris.
 14. The pipe cutting apparatus as in claim 8, wherein each cutting member is constructed of spring steel configured to bend inwardly toward said interior area so as to contact the tubing when said body member is inserted into the well casing.
 15. The pipe cutting apparatus as in claim 8, wherein said body member includes a cylindrical configuration and is configured to slide between the tubing and deep well casing. 